Coil lifter



Jan. 17, 1967 W. G. SOLEY COIL LIFTER Filed May '7, 1965 2 Sheets-Sheet l Jan. 17, 1967 w. G. soLEY 3,298,730

COIL LIFTE'R Filed May '7, 1965 2 Sheets-Sheet 2 United States Patent Q 3,298,730 COIL LIFTER Warren G. Soley, Greenfield, Wis., assignor to Indiana General Corporation, a corporation of Indiana Filed May I7, 1965, Ser. No. 454,152 7 Claims. (Cl. 294-655) This invention relates to lifting magnets and more particularly to lifting magnets for lifting odd shaped pieces such asannular pieces of magnetic material in coiled strip form and thelike.

Electromagnets for lifting both light and heavyweight material have been known for many years. However, there have been some problems identifiedy with the multipole electro lifting magnet for use in lifting coils of strip steel. One such probleml of the prior construction relates to dropping theelectric coils from their assembled position on the back plate. That is, the prior construction consisted of separate pole shoes, cores and bolts passing through the pole shoes for connecting the pole shoes, cores and coils lto the back plate of the magnet. Frequently the boltswould shear and not only would the pole shoesdrop, but the coil of the electromagnet would also fallout. The exposed electrical wiring would short against'the balance of the electromagnet and cause the possibility of serious injury to anyone within potential touching distance of the derrick or other actuating structure. In addition, the shape of the prior pole shoes is such that a relatively ineliicient concentration of flux lines result, thereby producing a substantially ineficient device.

It is a principal object ofthis invention to overcome the above noted disadvantages of the prior art and to provide an improved electro lifting magnet for coil strips. improved electro lifting magnet with a one-piece core Itv isanotherobject of this invention to provide an and pole shoe construction.

It is another object of this invention to provide an improved electro lifting magnet having improved means for mounting the one-piece pole shoe and core with the electricv coil to' the back plate of the magnet.

It is. still another object of this invention to provide an improved electro lifting magnet having an encapsulated replaceable coil structure.

And yet another object of this invention is to provide an improved electro lifting magnet with a pole shoe and core construction designed to accommodate the fastening means inv an improved manner.

Stillanother object' of this invention is to provide an improved electro lifting magnet having a novel pole shoe design.

And still another object of this invention is to provide an improved electro lifting magnet having pole shoes of a feathered and tapered design adapted to concentrate the lines of liux inl an improved manner.

And yetanother objectsof this invention is to provide an electro lifting magnet having an improved lift attaching arrangement for resisting transmission 'to the pole shoes of the effect of excessive shock blows.

And Astill another object of this invention is to provide an improved electroY lifting magnet that is highly eihcient in operation, is relatively inexpensive to construct and maintain, and is substantially trouble free in operation.

These and other objects and advantages of this invention will become apparent from the following specification wherein |reference is made to the drawings in which:

FIGURE lis a vertical plan view of the improved electro lifting magnet;

FIGURE 2 is a bottom plan view of the electro lifting magnet illustrated in FIGURE 1;

ICC

FIGURE 3 is a partial vertical cross sectional view taken alongfthe lines 3 3 of FIGURE 2; and

FIGURE 4 is a crossr sectional view taken along the lines 4-4 of FIGURE 3.

A preferred embodiment of the electro lifting magnet 1,0 of the present invention is illustrated and comprises a substantially circular body member 11 which may be of cast steel or other flux conductingmaterial and which is provided with a plurality of chain or cable connecting lugs 12 extending upwardly therethrough in a symmetrical arrangement about the axis of the body member. Chains 14 are adapted to be connected together at a point fairly close to the back of the body member 11 and to be connected to a hoist or derrick of a clamshell or the like for maneuvering the magnet from the position to another.

Mounted 0n the underside of the body member 11 is a plurality of circumferentially spaced and symmetrically disposed pole pieces 16, 17, 18 and 19 which are surrounded by a shroud or casing 21. The shroud 21 can be of suitable insulating material and can be either nonmagnetic or magnetic in characteristic and can be formed in a substantially circular shape as shown, or in a square shape with rounded corners around the pole pieces, either one being adapted to completely enclose the coils of the lifting magnet. If the magnet 10 is used around steel beams or poles it is advisable to construct the outer shell of steel to prlovide a shielding path for flux. On the other hand, if maximum strength is required, we would use a nonmagnetic side plate. The upper por-tions of the shroud are welded to the base plate and project freely downwardly from the outer edge portions thereof. The upper corner of the base plate is beveled or tapered as at 20. The shroud encloses the encapsulated coils but does not extend below the pole shoes 22 carried by the pole pieces.

Two of the pole pieces; namely, 16 and 18, have a north polarity or charge and two of the pole pieces, 17 and 19, are of a south polarity or charge. Accordingly, every pole piece has adjacent pole pieces of opposite magnetic polarity. Each pole piece is constructed in substantially the same manner as all of the other pole pieces and accordingly for the purposes of this description, only one pole piece 19 will be described in detail.

Referring in particular to FIGURES 3 and 4, pole piece 19 has a pole shoe 22 integrally formed with and lying in a plane substantially perpendicular to the axis of a pole core 24 which has the extended fastening portion or lug 12 carried thereby. Each pole shoe 22 has a body portion 25 with a substantially planar pole face 26 having parallel side edges 27, 28 and rounded ends 29, 30. The side edges 27, 28 are feathered or beveled outwardly and upwardly therefrom to form the feathered or beveled side walls 32, 33. The rear end 29 is also beveled upwardly at 35, see FIGURE 1, and has an indented recess 36 formed around the upper portion of said body portion 25. The pole piece 19 has the pole face 26 extending from the end 29 which is substantially flushwith the shroud 21 to a point fairly close to the center axis of the lifting magnet.

The pole shoes 22 have their planar pole faces 26 disposed radially outward from the vertical axis of the magnet. The side walls 32, 33 of the pole shoes are feathered or tapered from the planar faces 26 to the body of the shoes such that energizing the magnet so that adjacent poles will have opposite polarity will cause a concentration of the lines of flux in the arm of the coil and will reduce leakage liux between adjacent poles.

The upper portion of the body 25 of the pole shoe 22 is cast integrally with the cylindrical core member 24 and has a pair of grooves or slots 38 cut longitudinally into the sides of the core along the length thereof. The

slots 38 are aligned with apertures 39 in the pole shoe A22,an,d with apertures 41 in the body member llvsuch that a fastening means or bolt 43 can pass therethrough with a bolt head 44 seated in the recess or countersink 45. The depth of the recess 45 and the thickness of the bolt head 44 are such that the bolt head 44 will not protrude beyond the surface of the pole face 26. A nut 47 is threaded on the extended end of the bolt 43 to secure the pole piece 19` on the body member 11.

Positioned around the core 24 is an electric coil 50 Vwhich is composed of an inner cylindrically shaped sleeve 51 having slight recesses 53, 54 respectively cut into the top and bottom outer cylindrical surface for receiving wall 56 of the apertures through the opposed end discs 58. The end discs 58 are secured in said recess 53, 54 and are attached to an outer encasing sleeve 59 by means of welding or the like. Wound about the inner sleeve 51 -is a plurality of spaced energizing windings 60 which are electrically connected to the electric outlet 62 for the pole piece. The windings of the coil are Well known in the art. Any well known coil 60 construction, together with any well-known method of interconnecting coils of various pole pieces 16, 17, 18, 19 are acceptable for this design. TheA encapsulation of the coils in the housing defined by the sleeves 51, 59 and end discs 5S, 58 keeps the coils substantially trouble free from dirt and moisture and makes an easily replaceable unit when necessary. A supporting disc 64 is mounted in the recess 36 formed in the back surface of the pole shoes 25 for supporting the coils 50 of each pole piece. The encapsulated coils 50 are slipped over the core 24 of the pole shoes 22 so that the bottom disc 58 bears against said supporting disc 64 on the pole shoe 22. The inner sleeve 51 of the coil 50 acts as an axial spacer between the pole shoe 22 and the body member 11 so that when the nut 47 is tight ened on the fastening means 43 for holding the pole shoe 22 to the body member 11, it will draw the pole shoe 22 up against said inner ksleeve 51 for holding the coil 50 in a substantially rigid position relative to the core 24.

The core 24 of the pole piece 19 has a slight offset which forms a supporting shoulder 66 bearing against the under surface of the body member 11. The fastening portion or attaching lug 12 is cast integrally with the core 24 and extends through the opening 68 in the body member 11. The lug 12 has an aperture 69 through the exposed portion thereof and is split along a radial line such that a link 70 of a chain 14 can t in said split so that a bolt or rivet 72 can pass through the aperture 69 for attaching the chain 14 to the pole piece.

The apertures 68 of the body member and the lugs 12 of the pole pieces 18 are positioned relative to the center of the lifting magnet device in such a way that shock loads or blows will be resisted, thereby prolonging the life of the device. Relatively little or no play is allowed between the lugs 12 and the body member, thereby reducing relative flexing between the parts.

With my improved design, each pole shoe 22, the core 24 and attaching lug 12 are all cast integrally in one piece and are assembled to the body member 11 for supporting the coils 50 by means of the bolts 43 in such a way that the coils cannot be dropped when a bolt 43 shears off, as was true in prior constructions. My improved design permits shearing of one or more bolts 43 without dropping the pole shoes 22 and coils 50 since the one-piece pole shoe, core and lug are all connected together and to the lifting chain 14 whereby the weight of the magnet is carried by said pole shoes. The only way a coil and pole shoe can be dropped now is by shearing the bolts 43 and core 24. With the amount of mass involved and the relatively rigid construction, the possibility of shearing both the bolts and the core is quite remote.

The coils 50 are each connected electrically through terminals 62 to a common box and subsequently to a master control whereby power can'be supplied to the magnets and can be controlled in an accepted fashion.

With the more highly concentrated lines of iiux from the pole pieces 16, Y17, 18 and Y19, it is possible to lift heavier and odder shaped coil strip rolls, the additional lines giving greater working strength to the magnet.

I claim:

1. In an electromagnet for lifting magnetizable articles, having a base plate, a plurality of positive magnetic pole pieces and a plurality of negative magnetic pole pieces carried by said base plate and being electrically energized in such a way. that adjacent poles will have opposite polarity, said pole pieces being spaced apart from one another circumferentially and having a shroud depending from said base plate for encircling said pole pieces in combination with means for mounting said pole pieces on said body member comprising a cast one-piece means having a core member and a transversely disposed pole shoe formed therewith, a coil having an inner sleeve surrounding the core member and 'resting on said pole shoe, said coil being encapsulated within an outer housing attached to said inner sleeve, the upper portion of said core member extending through an opening in said base plate and being provided with a fastening means above said plane of the base plate, means connecting said pole shoe to said base plate for supporting said pole shoe and coil on said base plate, and lifting means connected to the fastening member on the core means whereby the electromagnet is lifted through the core member a-nd pole shoes.

2. An electromagnet having a body member, at least one positive magnetic pole piece and at least one negative magnetic pole piece carried by said body member, a coil for each pole piece connected in such a way as to provide adjacent pole pieces with opposite polarity, said coils being formed on a hollow sleeve and being encapsulated within a cylindrical housing, means for mounting said pole pieces on said body member, said means comprising cast one-piece core and pole shoe members, one of the core portions of said core and pole shoe members extending through the hollow sleeve of one of said coils and having the pole shoe portion of said core and pole shoe member transversely disposed relative to the axis of the core in overlapping relation with the underportion of the coil so as to support said coil, fastening means connected to said pole shoe portion and to said body member and extending through longitudinal slots formed in the sides of each of said core portions, each said pole shoe portion having a' planar face portion with upwardly tapered side portions, and means connected to said core portions for lifting said electromagnet.

3. An electromagnet having a body member, at least one positive magnetic pole piece and at least one negative magnetic pole piece carried -by said body member, a coil for each -pole piece connected in such a way as to provide adjacent pole pieces with opposite polarity, means for mounting said pole pieces on said body member, said means comprising a cast one-piece member having a core portion and a pole shoe portion, the pole shoe portion lying in a plane lperpendicular to the axis of the core portion, and extending radially outwardly in overlapping relation with said coil so as to support said coil, said core portion being positioned within and extending through said coil, fastening means connecting said pole shoe portionl and said "body member, keach said pole shoe portion A having a planar face portion' with upwardly tapered side portions, and means 'connected to the upper end portion of said core portions forlifting saidelectromagnet.

4. An electromagnet having a .body member, at least one positive magnetic pole piece and at least one-negative 'magnetic pole piece carried by said tbody member, a coil for each pole piece connected in such a Way as to provide adjacent pole pieces with opposite polarity, means for mounting said pole pieces on said body memiber, said means comprising a cast one-piece member having a core portion and a pole shoe portion, the core portion extending through the center of one of said coils and having the pole shoe portion extending sidewardly from the lower end .portion of said core portion so as to overlap with and support the bottom of said coil, elongate fastening means connected to said pole shoe portion and to said body member for securing said pole shoe portion and coil to said body member, each said pole shoe portions having a pole face substantially in a plane common to the pole faces of all the pole shoe portions, the sides of said pole shoe portions -being tapered upwandly and outwardly from said pole faces whereby the concentration of the lines of flux from said pole shoes will be at a maximum.

5. In an electromagnet for lifting annular coils, a body member, a pair of positive magnetic pole pieces and a pair of negative magnetic pole pieces carried by said body member, all of said pole pieces being spaced apart from one another circumferentially, a shroud depending from the body member and encircling said pole pieces, a coil for each pole piece connected in such a way as to provide adjacent pole pieces with opposite polarity, in combination with means for mounting said pole pieces on said body member comprising a cast unitary one-piece member having a core means and a pole shoe means, said core means extending continuously through the center of one of said coils and having said pole shoe means transversely disposed with respect to the lower end portion of said core means in overlapping relation with the bottom of said coil so as to support said coil from below, the upper end portion of said core means extending through said body member and being adapted to be attached to lifting means for said electromagnet, and elongate fastening means having a head portion nested in said pole shoe means and extending through said coil to an attachment with said body member for fastening said pole shoe means, said core means and said coil to said body member, said pole shoe means having a base portion with sides diverging toward the center of the body member with a substantially planar rectangularly shaped pole face, the sides of said pole shoe means between said pole face and said base portion being feathered gradually from the wide end of the shoe toward the narrow end whereby the lines of flux from said shoes will have optimum concentration.

6. An electromagnet having a body member, at least one positive magnetic pole piece and at least one negative magnetic pole piece carried by said body member, a coil for each pole piece connected to an electrical source in such a way as to provide adjacent pole pieces with opposite polarity, means for mounting said pole pieces on said body member, said means comprising a cast onepiece member having a core extending continuously through the center of one of said coils and having a pole shoe transversely disposed relative to said core, said pole shoe extending outwardly from said core and beneath said coil so as to support said coil from below, and elongate fastening means extending through said pole shoe and through said body member for retaining said pole shoe, coil, core and body member assembled together, each said pole shoe having a planar face portion with divergin-g feathered side portions Ijoining with a truncated body portion of said pole shoe, the truncated end of said pole shoe being disposed toward the center of said electromagnet, and means connected to said body member for lifting said electromagnet.

7. In an electromagnet for lifting annular rolls of strip metal endwise having a body member, a -plurality of positive magnetic pole pieces and a ,plurality of negative magnetic pole pieces carried by said body member, all of said pole pieces being spaced apart from one another circumferentially and having a shroud encircling said pole pieces and depending from the peripheral edge portion of said body member in combination with means for mounting said pole pieces on said body member comprising a cast member having a unitary one-piece core and pole shoe structure, said core extending continuously through the center of a coil, the upper end portion of said core extending through said body member and having a fastening aperture in the exposed upper end portion thereof, said pole shoe extending radially outwardly below said coil so as to support said coil, elongate fastening means extending through said pole shoe along a slot in the side face of said core and through said body member, a head on said fastening means being countersunk in said .pole shoe and having a nut threadedly engaging the end portion of said fastening means beyond said body member for fastening said pole shoe, core and coil to said body member, each coil having electrical windings and being connected in such a way that some pole shoes will be of one polarity and adjacent pole shoes will .be of the opposite polarity, and lifting means connected through the apertures in the exposed end portions of the cores whereby the electromagnet can be lifted and moved for use.

No references cited.

BERNARD A. GILHEANY, Primary Examiner.

H. A. LEWITIER, Assistant Examiner. 

2. AN ELECTROMAGNET HAVING A BODY MEMBER, AT LEAST ONE POSITIVE MAGNETIC POLE PIECE AND AT LEAST ONE NEGATIVE MAGNETIC POLE PIECE CARRIED BY SAID BODY MEMBER, A COIL FOR EACH POLE PIECE CONNECTED IN SUCH A WAY AS TO PROVIDE ADJACENT POLE PIECES WITH OPPOSITE POLARITY, SAID COILS BEING FORMED ON A HOLLOW SLEEVE AND BEING ENCAPSULATED WITHIN A CYLINDRICAL HOUSING, MEANS FOR MOUNTING SAID POLE PIECES ON SAID BODY MEMBER, SAID MEANS COMPRISING CAST ONE-PIECE CORE AND POLE SHOE MEMBERS, ONE OF THE CORE PORTIONS OF SAID CORE AND POLE SHOE MEMBERS EXTENDING THROUGH THE HOLLOW SLEEVE OF ONE OF SAID COILS AND HAVING THE POLE SHOE PORTION OF SAID CORE AND POLE SHOE MEMBER TRANSVERSELY DISPOSED RELATIVE TO THE AXIS OF THE CORE IN OVERLAPPING RELATION WITH THE UNDERPORTION OF THE COIL SO AS TO SUPPORT SAID COIL, FASTENING MEANS CONNECTED TO SAID POLE SHOE PORTION AND TO SAID BODY 